Enantioselective Synthesis of Chiral α‐Alkylthiomalonates via a Phase‐Transfer‐Catalyzed α‐Sulfenylation of α‐Alkylmalonates

So Hyun Jung, Byungsoo Kim, Cheonhyoung Park, Jeongseok Kim, Min Woo Ha, Suckchang Hong, and Hyeung-geun Park*

Research Institute of Pharmaceutical Sciences and College of Pharmacy Seoul National University, Seoul, Korea

Asian JOC paper

A synthetic method for accessing chiral α‐alkylthio‐α‐alkylmalonates was successfully established. The enantioselective α‐sulfenylation of α‐alkylmalonates via phase‐transfer catalysis [N‐alkylthiophthalimide, 50% aq. KOH, toluene, −40 °C and N‐2′,3′,4′‐trifluorophenyl‐dihydroquinidium bromide] provided the corresponding α‐alkylthio‐α‐alkylmalonates in high chemical yields (up to 97%) and optical purities (up to 90% ee).

Asian J. Org. Chem. 2019, 8, 1732–1739

DOI10.1002/ajoc.201900346